Reading high V through resistor/cap casings

[Carsonmcw]

I'm working on an old Sovtek Mig 50. It's almost all original and it sounds great now that I've touched up some bad solder joints. While testing around in the amp I noticed on a few filter caps and a few resistors (all within the B+ line) I'm able to read anywhere from 125 to 350 dcv through the side walls of the components. When doing this on a couple resistors it'll make the amp screech horribly. I'm guessing this is a sure sign of faulty/leaky components. Though I'm getting accurate resistances and the B+ is what I would expect with this amp.
Just curious what anyone might know about this.
I can post photos if that is at all helpful.

 

[JonSnell Electronic]

Touching the odd resistor and it makes odd sounds is due to spurious noise generated by the load and feedback from the test lead used. One cannot test a resistance whilst powered with large amounts of DC. They must be tested when cold and totally discharged. Even then one may get incorrect readings.

 

[BinaryMike]

What kind of voltmeter are you using? Some voltmeters have extremely high input impedance, which means that they can 'see' voltage through low-grade insulation. My old Keithley 2000, for instance, has 10 gigohm input Z on the lower DC voltage ranges.

 

[Carsonmcw]

What kind of voltmeter are you using? Some voltmeters have extremely high input impedance, which means that they can 'see' voltage through low-grade insulation. My old Keithley 2000, for instance, has 10 gigohm input Z on the lower DC voltage ranges.

I'm using an ECG DM-38. Looks like 20M input impedance on all voltage ratings.